General English


  • The distance from peak to peak of a wave, whether of matter or of radiation. Multiplying wavelength by frequency yields a wave’s velocity.


  • noun the distance from the highest point of one wave to the highest point of the next


  • noun the distance between two adjacent peaks of a wave, equal to the speed divided by the frequency


  • The distance between two successive points in a sound or light wave that are characterized by the same phase of oscillation.


  • For a periodic wave, such as an electromagnetic wave, the distance between any point having a given phase, and the point having the same phase in the next cycle. It is the length of a complete cycle, and is usually measured from peak to peak, or from trough to trough. In the case of electromagnetic radiation traveling through space, it is equal to the phase velocity divided by the frequency. Usually expressed in meters or fractions/multiples of meters such as millimeters or kilometers. Its symbol is Λ.
  • abbreviationlambda (λ)
  • Symbol for linear charge density, or charge density (3).

Information & Library Science

Media Studies

  • noun a measurement of radio waves, describing the distance between the peak of one wave and the peak of the next.
  • noun in broadcasting, the wavelength of the fundamental radio wave used by a broadcasting station